A 2nd generation mobile communication means to transmit/receive a digitized audio and includes such as CDMA, GSM and the like. GPRS evolved from the GSM is proposed. The GPRS is a technology to provide a packet switched data service based on the GSM system.
A 3rd generation mobile communication means to enable to transmit/receive an image and data as well as an audio. 3GPP (third generation partnership project) developed a mobile communication system (IMT-2000) and adopted a WCDMA as a radio access technology (hereinafter abbreviated RAT). In Europe, the IMT-2000 technology and the radio access technology (RAT) e.g., WCDMA are called an UMTS (universal mobile telecommunication system) in total. And, UTRAN is an abbreviation of UMTS terrestrial radio access network.
Meanwhile, the 3rd generation mobile communication is evolving to a 4th generation mobile communication.
A long-term evolution network (LTE) technology standardizing by the 3GPP and an IEEE 802.16 technology standardizing by IEEE are proposed as a technology of the 4th generation mobile communication. A terminology “E-UTRAN (evolved-UTRAN)” is used by the LTE.
Meanwhile, all traffics occurred by a current user are hard to be handled even by the 3rd generation or the 4th generation mobile communication system in some point. Hence, a communication technology performed by IEEE 802.11, which is called WiFi, is recently disseminated. In the following description, it shall be described with reference to diagrams.
FIG. 1 is a diagram for showing a relationship between a mobile communication system and WiFi.
Referring to FIG. 1, a terminal 10 is locate at a coverage of a first base station 21 and at least one or more access points (AP) 31/32 are located at the coverage of a second base station 22. And, at least one access point (AP) 33 is located at the coverage of a second base station 23.
The terminal 10 may be able to access the first base station 21 to use a data service. Yet, the terminal 10 may be able to perform a search to access an access point (AP) if necessary. However, to continuously perform the search, in case that there does not exist an accessible access point near the terminal 10 as shown in FIG. 1, may cause a result of power waste of the terminal.
Meanwhile, a technology for saving power consumption in WiFi technology exists as a scheme for saving power in a manner of controlling a sleep mode and an idle mode in case of being connected (or associated) to an access point only and does not exist for a technology to search for the access point in case of not being connected to the access point.
On the other hand, although a search for an access point may be performed with a low frequency due to a power consumption of a terminal, there is a lot of cases that should utilize WiFi as much as possible depending on an application installed in a smartphone, which is recently spotlighted.
In particular, there is an application allowing a transit delay to some extent among applications of the smartphone. If an access point is searched no later than an allowed time for the transit delay of data, the application transmits data in a manner of accessing the access point. Yet, to continuously perform a search for the access point may have a drawback causing a significant power consumption.
Therefore, it is necessary to efficiently manage a power consumed for searching for an access point based on WiFi.